Many types of hearing tests are available and the audiologist will decide which test to select based on the age of the client, the clinical situation, medical considerations and the information that is required. The following are explanations of some selected procedures (although many other tests are conducted, they are too numerous to explain here):
- Pure-tone audiometry – this is the most common procedure usually used in screening and diagnostic testing. It can be conducted in adults and children aged 3 years and older. In this test, the client is required to listen and respond to tones (beeps) of various pitch and loudness. A pure-tone audiometer, headphones and bone conductor are used to conduct this test.
- Free field or sound field audiometry – this test is used in young children who cannot participate in a pure-tone hearing test. In this test, the child usually sits on the Parent’s lap. The Audiologist presents a tone via a speaker. When the child responds to the sound, a puppet box (near the speaker) is lit up.
- Acoustic admittance/ impedance testing – this test evaluates the middle ear. In this test, a small probe tip is inserted into the ear canal and air pressure is pumped into the ear. The client is required to be still for a few seconds whilst the test is conducted. The client does not need to respond in any way.
- Speech tests – this test evaluates the client’s ability to hear speech. The client may be required to repeat words, sentences or parts of the sentence in quiet conditions or conditions when the speech has been filtered or there is background noise. These tests are also used to evaluate Central Auditory Processing Disorder (CAPD).
- Otoacoustic Emissions (OAEs) – this test is an objective test and thus no response from the client is required. In this test, a small probe tip is inserted into the client’s outer ear canal. The client will hear a series of tone pips. This test gives the audiologist information about the client’ sinner ear status (particularly the hair cells of the cochlea).
- Auditory Brainstem Response (ABR) – this test is used to evaluate the neural (nerve) firing of the CANS. An ABR machine, electrodes and a headphone are used. The client is required to be very still during this procedure and young children may require sedation. The screening version of this test is used to screen the hearing of newborns under the Universal Hearing Screening program.
Note: Audiological tests are not painful in any way and there is no risk associated with having any of the Audiological procedures mentioned above. Audiologists abide by a code of conduct and in accordance with this code, equipment should be calibrated and cleaned regularly.